Abstract
Surface mass balance is the most relevant glacier characteristic in terms of climate. Accumulation and ablation at the glacier surface are primarily driven by atmospheric conditions. Monitoring glacier mass balance can thus help to observe changes of the state of the atmosphere. Direct seasonal to annual glaciological measurements of glacier mass changes are available for a limited number of glaciers worldwide. Regional- and global-scale geodetic mass balance data were obtained recently up to semi-decadal resolution. Glacier recess worldwide has occurred more frequently in recent decades as a response to temperature increases. There are considerable interannual and regional variations to this global trend due to the interplay of other factors, such as changes in other meteorological variables in combination with static, morphotopographic drivers, as well as internal glacier dynamics. Meteorological parameters such as atmospheric humidity, incoming shortwave and longwave radiation, and near-surface wind speed and direction also influence glacier mass balance. However, changes to these meteorological variables and the interplay with morphotopographic characteristics and their effect on glacier dynamics are still understudied both from an observation and modeling standpoint.